Overinterpretation of gastroduodenal motility studies: two cases involving Munchausen syndrome by proxy

An ANMS-NASPGHAN consensus document on esophageal and antroduodenal manometry in children

BACKGROUND

Upper gastrointestinal symptoms in children are common and motility disorders are considered in the differential diagnosis. High resolution esophageal manometry (HRM) has revolutionized the study of esophageal physiology, and the addition of impedance has provided new insights into esophageal function. Antroduodenal motility has provided insight into gastric and small bowel function.

PURPOSE

This review highlights some of the recent advances in pediatric esophageal and antroduodenal motility testing including indications, preparation, performance, and interpretation of the tests. This update is the second part of a two part series on manometry studies in children (first part was on anorectal and colonic manometry [Neurogastroenterol Motil. 2016;29:e12944]), and has been endorsed by the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN) and the American Neurogastroenterology and Motility Society (ANMS).

Motility Disorders in Children

Gastrointestinal motility disorders in the pediatric population are common and can range from benign processes to more serious disorders. Performing and interpreting motility evaluations in children present unique challenges. There are primary motility disorders but abnormal motility may be secondary due to other disease processes. Diagnostic studies include radiographic scintigraphic and manometry studies. Although recent advances in the genetics, biology, and technical aspects are having an important impact and have allowed for a better understanding of the pathophysiology and therapy for gastrointestinal motility disorders in children, further research is needed to be done to have better understanding of the pathophysiology and for better therapies.

Munchausen syndrome by proxy: ongoing clinical challenges

In 1977, Roy Meadow, a pediatric nephrologist, first described a condition he subsequently coined Munchausen syndrome by proxy. The classic form involves a parent or other caregiver who inflicts injury or induces illness in a child, deceive the treating physician with fictitious or exaggerated information, and perpetrate the trick for months or years. A related form of pathology is more insidious and more common but also damaging. It involves parents who fabricate or exaggerate symptoms of illness in children, causing overly aggressive medical evaluations and interventions. The common thread is that the treating physician plays a role in inflicting the abuse upon the child. Failure to recognize the problem is common because the condition is often not included in the differential diagnosis of challenging or confusing clinical problems. We believe that a heightened "self-awareness" of the physician's role in Munchausen syndrome by proxy will prevent or reduce the morbidity and mortality associated with this diagnosis. In addition, we believe contemporary developments within the modern health care system likely facilitate this condition.

Prolonged monitoring of esophageal motor function in healthy children

OBJECTIVE

To describe diurnal variations of esophageal motor function in children using combined ambulatory 24-hour esophageal manometry and continuous intraluminal pH measurement (MP24).

METHODS

Medical records of all patients referred for the performance of MP24 from 1995 to 2002 at a tertiary care center were reviewed. Patients were selected retrospectively for this study using the following inclusion criteria: (1) no dysphagia, (2) normal upper gastrointestinal barium radiograph, (3) normal esophagogastroduodenoscopy and biopsies, (4) normal stationary esophageal manometry, (5) normal esophageal pH probe, and (6) no gastrointestinal pathology appearing after long-term follow-up. Data from the MP24 of these children were retrospectively analyzed for differences between meal, upright, and supine periods using nonparametric univariate analysis.

RESULTS

One hundred twenty-three children had MP24 during the study period. Eleven met the criteria for normality and were included. Their mean age was 12.4 +/- 1.5 years. The number of contractions/minute in the upper, middle, and lower esophageal body differed significantly during meals and in the upright and supine periods (P < 0.01). A significant increase in motor activity occurred during meals (P < 0.01). There was less motor activity observed in the supine position than in the upright position (P < 0.01). There were significant differences in effective (P < 0.05) and total propagated peristalsis among the meal, upright, and supine periods (P < 0.01), with the largest percentage of propagated contractions observed during meals.

CONCLUSION

This study provides the first information on prolonged esophageal motor activity in pediatric patients without esophageal disease. MP24 in children demonstrates significant diurnal variations in esophageal motor function that is similar to the findings in studies of healthy adults.

The deceit continues: an updated literature review of Munchausen Syndrome by Proxy

OBJECTIVE

This article presents an updated review of the literature of Munchausen Syndrome by Proxy (Factitious Disorder by Proxy, MBP).

METHOD

Four hundred fifty-one cases of MBP were analyzed from 154 medical and psychosocial journal articles.

RESULTS

Typical victims may be either males or females, usually 4 years of age or under. Victims averaged 21.8 months from onset of symptoms to diagnosis. Six percent of victims were dead, and 7.3% were judged to have suffered long-term or permanent injury. Twenty-five percent of victims' known siblings are dead, and 61.3% of siblings had illnesses similar to those of the victim or which raised suspicions of MBP. Mothers were perpetrators in 76.5% of cases, but as knowledge of MBP grows a wider range of perpetrators is identified. In a small number of cases, MBP was found to co-exist with secondary gain or other inflicted injury.

CONCLUSION

Although published cases form a non-random sample, they add to knowledge about MBP and validate claims that it occurs. More knowledge about non-medical aspects of MBP, and more pooling of data, is desirable.

Discriminating pediatric condition falsification from chronic intestinal pseudo-obstruction in toddlers

Pediatric condition falsification may masquerade as chronic and serious digestive disease, including chronic intestinal pseudo-obstruction. The purpose of this study was to define clinical criteria to discriminate between these two conditions. We compared medical records of 8 pediatric condition falsification victims to those of 14 children with chronic intestinal pseudo-obstruction. Clinical features suggesting pediatric condition falsification in toddlers presenting with chronic and severe digestive complaints included (a) daily abdominal pain, (b) illness involving three or more organ systems, (c) an accelerating disease trajectory, (d) a reported history of preterm birth, (e) absence of dilated bowel on x-ray, (f) normal antroduodenal manometry, and (g) no urinary neuromuscular disease. These results suggest that a diagnosis of pediatric condition falsification may be suspected in toddlers presenting with a phenotype for enteric neuromuscular disorders by features in the clinical history, symptoms, and signs.

Long-term results of intestinal transplantation for pseudo-obstruction in children

PURPOSE

The aim of this study was to determine long-term results of intestinal transplantation in children with pseudo-obstruction, particularly when stomach and colon are not part of the allograft.

METHODS

The authors conducted a case-record review of all children who underwent transplantation at our center for a primary diagnosis of pseudo-obstruction. Supplementary information was obtained from outpatient charts, computerized database, and telephone survey of parents.

RESULTS

Six small bowel and 3 liver-small bowel transplants were carried out in 8 patients between 1993 and 1999. Median follow-up is 40 months (range, 13 to 73 months). Median age at transplantation was 2.7 years (range, 0.7 to 12.8 years). Median graft survival in this series is 15 months (range, 1 day to 71 months). Stomach and colon were excluded from all allografts. Two children died 5 and 368 days after transplant and 2 graft losses occurred in 1 patient. Two children had lymphoproliferative disease; both are alive with functioning grafts. Five survivors with functioning grafts receive full enteral feedings at home. Four of the 5 have had ileostomies closed, and 3 have normal bowel movements.

CONCLUSIONS

Intestinal transplantation without stomach or colon provides children with chronic intestinal pseudo-obstruction with a good quality of life. The underlying disease poses special challenges in management.

Munchausen syndrome by proxy

Munchausen syndrome by proxy is the most difficult form of child abuse. It carries substantial morbidity and mortality. The diagnosis relies on appropriate suspicion and careful investigation. The psychological illness/need of the perpetrator is the main clinical feature. Early recognition and appropriate intervention prevent further abuse and criminal actions.

Analysis of fasting antroduodenal manometry in children

Antroduodenal manometry has been used to determine the pathophysiology associated with signs and symptoms of gastrointestinal motility disorders. The diagnostic value of antroduodenal manomentry has been limited by the paucity of data from normal children. In this study, we compared antroduodenal manometry findings from 95 patients with symptoms suggesting a gastrointestinal motility disorder to 20 control children. Phase III of the migrating motor complex (MMC) was less frequent in patients (P < 0.05), especially in those who required total parenteral nutrition (P < 0.001), than in controls. Abnormal migration of phase III and short intervals between phase IIIs were more frequent in patients than in controls (P < 0.01 and P < 0.05, respectively). During phase II, persistent low-amplitude contractions and sustained tonic-phasic contraction were found only in parenteral-nutrition-dependent children. Short or prolonged duration of phase III, absence of phase I following phase III, tonic contractions during phase III, low amplitude of phase III contractions in a single recording site and clusters of contractions or prolonged propagating contractions during phase II were not more frequent in patients than in controls. We conclude that there are five manometric features having a clear association with pediatric gastrointestinal motility disorders: (1) absence of phase III of the MMC, (2) abnormal migration of phase III, (3) short intervals between phase III episodes, (4) persistent low-amplitude contractions, and (5) sustained tonic-phasic contractions.

Gastrointestinal motility in neonatal and pediatric practice

Caring for children with gastrointestinal motility disorders requires an understanding of age-related changes in gastrointestinal function and in the clinical expression of disease. Successful evaluation of the child with a gastrointestinal motility disorder necessitates an approach that takes into account not only the child's symptoms, but also the stage of development. This article reviews the ontogeny of gastrointestinal motility; the techniques available for the study of gastrointestinal motility in children; and the presentation, pathophysiology, and treatment of pediatric functional bowel diseases. Differences in children compared to adults in performing and analyzing motility testing and in evaluating motility disorders are emphasized. A more complete understanding of pediatric motility disorders may provide important insights in approaching functional bowel diseases in adults.

Age-related changes in colon motility

To assess age-related changes, we analyzed 32 colon manometry studies of children referred for motility studies and found not to have colonic disease. Colon motility was recorded by endoscopically placed water-perfused catheters. There was an inverse correlation between the number of high-amplitude propagated contractions and age, before and after administration of a meal; colonic contractions different from the high-amplitude propagated contractions increased with age.